I was told by a solar company that PWs are dedicated to specific circuits and not the whole panel. So essentially it would only power the fridge, oven, specific outlets etc. Is this true?
A single Powerwall can support up to a 5kW load. Multiple Powerwalls can be installed in parallel i.e. two Powerwalls can support a total load of up to 10kW and so on..
While you are grid connected the PW will support up to this load and the extra will be drawn from the grid. So in this scenario there is no reason why you should not connect the PW to all your loads.
If you require the PW to support your home when there is a power outage then you should try and avoid exceeding the rate at which the PW can supply power. In this scenario you may well want to exclude some heavy loads from your PW supported circuits. Of course separating the circuits removes some of the flexibility you may required during a power cut but unless you manage the loads well you may exceed the ability of the PW to support them. I do not know what the PW does in this case but I would expect it to shutdown, leaving you without power until the PW restarts.
Giving a concrete example: I have two Powerwalls and my whole house is backed up. When the power goes out, the only thing I have to worry about is not to use more than 10 kW worth of appliances at the same time.
Let's say I exclude EV charging (ie. EV charger is between gateway & meter) from being battery backed during an outage. During normal usage, will the Powerwall still supplement utility power? Or will it only supply power to circuits behind the gateway?
I guess the same question goes for solar. If I need to quickly charge my EV during the day, will solar switch from charging the batteries to helping offset EV charging? Despite the EV circuits being "outside" of the gateway?
Each Powerwall can back up loads in your breaker box with a 30A rating or less, 2 60A and so on.
@jr In a partial backup setup, the powerwalls power the whole house regardless of the circuits dedicated to it in your subpanel that Tesla installed as part of the “partial backup”
Only in a grid outage, does the situation occur that only the circuits dedicated to the powerwall will have power. So in a grid outage, if your AC or Ev charger are NOT on the powerwall subpanel, they won’t have power in a “grid down situation”. Note, the powerwall will provide power to these circuits when the grid is up
Per your final question, the way the setup works is
1). Solar first
2). Powerwall second
3). Grid only when both solar + powerwall can’t provide enough power that “all circuits” are demanding.
3a). You can prevent powerwall from being the 2nd source by setting it to “backup only) or setting the reserve high enough in self power mode that will send it to standby and thus the grid will kick in